Amp question

[fbrdphreak]

It's been a while since I played with subs & amps at all, and my memory is fuzzy.

If I'm looking at running two 4-Ohm subs on a mono amp, does the RMS output at 2-Ohms need to match the RMS power rating of one sub or two combined? If the sub is rated at 300W RMS and I'm going to run two, does the mono amp need to push 300W RMS or 600W?

600....right?

 

[Howard]

You could run 10W if you wanted. Power output doesn't need to match power handling.

EDIT: If you run them in series, the impedance will double (assuming they are the same). Running them in parallel halves the impedance. Halving the impedance will double the power from a solid-state amp if the amp has sufficient current capability.

 

[thomsbrain]

Originally posted by: Howard
You could run 10W if you wanted. Power output doesn't need to match power handling.

EDIT: If you run them in series, the impedance will double (assuming they are the same). Running them in parallel halves the impedance. Halving the impedance will double the power from a solid-state amp if the amp has sufficient current capability.

Correct.

But either way, the max power handling of the speakers will be the total of each speaker combined. In your example, it would be 600 watts. If you wire in series, the max amp would put out 600 watts at 8 ohms (which would be a really powerful amp). If you wired in parallel, the max amp would put out 600 watts at 2 ohms (which would be a comparatively weaker amp). Not all amps can handle 2 ohm loads, but most sub-oriented amps can.

You can always use a more powerful amp than that, but if you turned it up all the way, you'd risk speaker damage. Some will say that using a smaller amp and turning it up all the way will also damage the speakers because clipping (amp distortion) is supposedly bad for the speakers. To that, I must respond that nearly every good guitar sound was achieved by running the amp at full volume with a massively overdriven input signal, so that the output was a pile of clipping carnage, and the cheap paper speaker cones that guitar speakers use never seem to complain.